According to the article I read people who have higher levels of stress can affect their ability to do routine in the gym. The researchers found that being stressed out could reduce a person's ability to adjust to a new training program. A study conducted at the University of Texas showed that people with lower levels of stress had larger strength gains after doing the bench press and squat than participants with higher levels of stress. Next time you plan to try another routine, resolve any problems you may have in your life. Reduce your stress, try meditation before you decide to go back to gym and hit the weights.